Treatment of the residue from gas purification known as crude ammoniac.



llaUUllS K'JHARIJES BUNITEAU, 035 El Itl'c Brewing.

To 0:32 whom tmay coiecem:

Be it known. that We, Louis (lemme Eonueen and Vision EMILE l-lesnusneum, citizens of the Republic of France, and resi dents of, the former, 19 Rue tle'le Legion dHonneur, St. Denis, Seine, end. the letter, 53 Rue Vallier, LGVELllOlS-PQYIEiJ, Seine, in

the said Republic, both chemists, heve in-' the residue from gas notification known etude enunoniec. The term crude em monies is intended, to cover ineteriels which have served for the purification of illumineting gas and which may he of twokintis:

' first, the Leaning mixture, composed of sul fate of iron, chalk and sawdust; unfit seeontl, oxid oi iton.

lnprooesses hitherto useol there has been extracted item the Sfilldfi eininonieo eit the sulfur to the exclusion of the otv products or the Prussian blue, but no indus trial :orocess has been available for extracting oonoui'rently all the useful constituents of this materiel.

' The process forming the Subject matter of this invention comprises four sueoeseive operations which, owingto the solvent seiectecl, to the eiiicaioy oi the reactions used for the separations, entl finally to the order etlonteo. introduc the agents, retluoe to a minimum the Waste operation and extract practically the Whole of the matters eonteinerl in the etuole materiel. These operations follow one another in this oitlor:--

. Desiccetion of the uutle materiel. Extraction of sulfur.

Extraction of emmonieca-l salts.

. Preparation of Prussia-n blue.

I. Dcsicoation of the crude material.

fiipecifieetion. otters Patten-toot i 115, ll E lie,

upplieutlenflt n'ilft' wi l. Sex-mine.fietlltl,

stirred the While The steam and Ere-e emiuonie expelled xii-e condensed.

ron 1' leis 'illQll? suitably collected and i "3 i'ying operation may he omitted Witoout ei feoting the succeeding operations.

solution in the solvent.

41.11 eithei" case etteir" the sulfur has been h of the solvent is coniitguitl thus: ohtzilnecl 1s eetmcti'sm of me omiitom'accl eaZts-.

e iresiclue item the cl -sulturizing op -n lei l with tepid weteito which shoulde ecltletl the slightly eniinoniecel confiensecl Wet-e1 rletivecl from the preliminary desiccation l When the extraction. is juclgerl to be suilioient the liquid containing one o wit is we with llil'ifiif) U108 the eh is ireeovei'etl F/llilloi. 21 n or its a su table ammonia by ehsotption with the itoown mennei'.

it is j "sole to lime-in the torn 0t milk oi l ne to? heating directly the erurle mess after oleeulturize-tioe; this, inocle of operation has the two-fold efiect o'l; liberating the emmonieea-l nitrogen iincl rendering soluble the Eei-i-o oyenicls by transforming tlol impure and insoluble :teiro-cyenid of iron into the soluble culcium tei'i'o-eyonid.

4. Ecctmczfcn of time Pew-950m hgT/ue.

VJhen the preceding treetinent hes been eiieetetl w th lune, the solid. residue from the treatment is inixetl with weterfio'n slaked lime. The muss ie then heated to ehout 1100 C. by means of e.- ourwnt-of steam. Under the action oi? the lime il llm term eye-toil ii (F or Prussian blue contain ed in the crude mess is transformed into the soluble calcium ferro-oyun i l.

The crude leached mess containing the calcium ferro-cyanid in solution, obtained either in the manner last described or in that previously described directly the ammonia has been liberated, is decanted so to sepsrate the liquid fronthe insoluble portion. The solution is then boiled, for example by s com and there is added potassium chlorid. A. crystalline precipitate of the double ferrocyonid of calcium and potassium Which is very little soluble in water soon appears and it is of a specific gravity decidedly higher than lhut of the liquid it settles rapidly. After cooling, the liquid. is siphoned from the precipitate, which is then washed with cold Water and decanted lVater is then added and the mixture heated to boiling and. treated with slight excess of sodium carbonate. The double fe ro-cysnid of cal; cium and potassium is thus decomposed with precipitation of insoluble calcium oarbonate and formation of an alkaline ferrocyanid (double ferro'cynnid of potassium and. sodium) which remains dissolved. A'Iter cooling, the liquid. is'separated by decsntation from the precipitate.

This quid is then poured into it solution of uric salt, whereupon so obundunt precip ate formed which is preferably ')ET-OI-Il llZG(l, for example by means of pure sodium hypochlorite or by hydrogen Jeroxid, so as to obtain Prussian blue.v 'lhis latter is suitably Washed and decanted, then dried l. he Prussian blue is fluidly passed.

through. the stove at a. temperature 01 30 -230 C. and. may be at the some time subjected to the scion of a vacuum.

The .finul solid residue from the crude muterial contains a suitable proportion of oxid of iron so hot the waste from the men- 'l a commercial value from u'l zicture has the point of rim: of the possible utilization the iron ving thus described our invention and the box; means. we know of carrying the suns into prurticol effect, we clsim:-

1. A process for the total extraction of the industrial chemical products contained in the residue from purification known us crude uminouiao, which. process consists in first extracting the sulfur by means of a solvent of the class of nou-infiumnntble chloriuu'ted or clilm'ltl solvents, then driving out the anmuml: sol nitrogen by means of line, then rendering soluble the ferro-oy amid hv means o 1' milk of lime, then treating the solution sm-cessively with potassium chlorid and sodium car onate for the purpose of renderingthe 'lerro-cyunid in the first instanc insoluble, and then soluble in order lo sepurulo it from forehrn mz'iteriels, hon prccipiluling the i' -l||.-c f,':jihid 2t :2: lesson ferric salt and finally peroxidizing the precipitate obteincdto transform it into Prussian blue.

A. process for the total extraction of the industrial chemical products, contained ferso-cyunid by'milk of lime, then treatingthe solution successively with potassium chlorid and sodium carbonate With the object first rendering the ferro-cysnid insoluble and then soluble so as to separate it from foreign materials, then precipitating the :l errocyanid by means of a, ferric salt and. finally peroxidizing the precipitate to transform it into Prussian blue.

3. Process for the total extraction of industrial chemical products from crudeammouiuc, which consists in first desicoeting the crude mass in order to recover the free ammonia, then extracting the sulfur by means of a solvent of the class of noninliomnisble chlorinated or chloridsolvents, then driving" out the ammoniscsl nitrogen by means of lime, then rendering" soluble the ferro-cyanid by mild: of lime, then tresting successively the ferro-cyanid solution with potassium chlorid and sodium csrbonuts for the purpose of first rendering in soluble and then soluble the ferro-cyanid so to separate it from foreign materials, their precipitat ng the ferro-cyanicl by means of n ferric salt and .linelly peroxidizing the precipitate to transform it into Prussian blue.

l. ulc process for the total extraction of in dustrisl chemical products contained in crude einmoniac, Which process consists in extracting the sulfur by means of boiling triohlorethylene for dissolving the sulfur; then. driving out the enunoniscsl nitrogen by means of lune, then rendering soluble the ferro-cyunid by milk of lime, then treating successively the ferro-cyanid by potassium chlorid and sodium carbonate so as to first render the ferro-cysnid insoluble and then soluble so as to separate from it the foreign materials, then precipitating the ferrocyunid by a. ferric salt and finally peroxidizing the precipitate to transform it into Prussian blue.

5. A process for the total. extraction of industrial chemical products contained in crude ainrnoniee, whichprocess consists in first extracting the sulfur by means of :1 solvent of the class of non-inflammable chlorinated or'chlorid solvents, then drivin out the animoniscul nitrogen by means of lime, then rendering soluble the ferrollll 

